NASA tests nuclear powered space travel

American scientists have tested a type of nuclear fission technology which could be used on space flights. It is the first experiment to produce electricity with a nuclear reactor system meant for space since 1965.

The team from NASA and the USA’s Department of Energy demonstrated the first use of a heat pipe to cool a small nuclear reactor and power a Stirling engine.

The DUFF project, or Demonstration Using Flattop Fissions experiment, produced 24 watts of electricity. It works with heat pipe technology invented at Los Alamos in 1963.

A heat pipe is a sealed tube with an internal fluid that can efficiently transfer heat produced by a reactor with no moving parts. A Stirling engine is a relatively simple closed-loop engine that converts heat energy into electrical power using a pressurized gas to move a piston.

The scientists say using the two devices in tandem can create a simple, reliable electric power supply that can be adapted for space applications.

Los Alamos engineer David Poston said: “The nuclear characteristics and thermal power level of the experiment are remarkably similar to our space reactor flight concept. The biggest difference between DUFF and a possible flight system is that the Stirling input temperature would need to be hotter to attain the required efficiency and power output needed for space missions.”

Marc Gibson of NASA Glenn added: “The heat pipe and Stirling engine used in this test are meant to represent one module that could be used in a space system. A flight system might use several modules to produce approximately one kilowatt of electricity.”

NASA’s exploration robot on planet Mars, the Curiosity rover, is partly powered by nuclear. Current space missions typically use the same amount of electricity as one or two light bulbs. Scientists believe the availability of more power could transmit mission data back to Earth more quickly or allow more instruments on a spacecraft to be operated at the same time.

Almost all deep space missions are nuclear powered out of necessity. For example, Voyager, Cassini, Galileo, Mars Curiosity Rover, etc., all use RTGs (radioisotope thermoelectric generators). Solar intensity is too low once you pass the orbit of Mars making solar collector arrays increasingly inefficient, unwieldy, and impractical. Chemical batteries are also too inefficient and too heavy. The only real solution is to use RTGs, and for larger power needs, small reactors. In addition to providing mission enabling electrical power, they also produce heat needed to keep spacecraft operational in harsh environments. The potential risk to life and safety is always a primary factor… these systems are quite safe and risk of harm is extremely low. RTGs have been proven to be extremely reliable and safe through many decades of use.